The present invention relates to a method for forming a pattern in a metal workpiece. More particularly, the present invention relates to a method for forming a minute pattern in a metal workpiece using a photolithography process and an electro-chemical etching process.
A laser process or a super-drill process is typically used to form a circular, minute pattern in a workpiece. In contrast, a non-circular, minute pattern is typically formed by an ion beam milling process. However, these conventional processes do not work well when applied to a metal workpiece.
The laser and super-drill processes suffer from similar problems which include: (a) the oxidation of the workpiece surface by heat generated during the process; (b) non-uniformity in circular patterns, and the resulting mismatch between circular openings formed on opposite sides of the workpiece; (c) the impossibility of forming non-circular, minute patterns; and, (d) the complexity and cost of the required equipment.